Sparking indicator.



w a? R m n A 'L'IORNEY C. E. HARLAN. SPARKING INDICATOR.

APPLICATION FILED 351N215, 1914.

. Patented May 25 SHEET 2.

2 SHEETS IN VENTOR ZZazzdZzE a/Za/z. I

WITNESSES ATTORNEY UNITED STATES PATENT oFFIcE.

ennui) E. neiiLAnfor wnrsonvxnm, CALIFORNIA, ASSIGNOR or ONE-HALF TWILLIAM.H. AMES, or WATSONVILLE, CALIFORNIA.

SPABKING INDICATOR.

' State of California, have invented new and useful Improvements inSparking Indicators,

of which the following is a specificatiom This invention relates to asparking indicator.

The object of the present invention is to provide a simple portabletesting instrument for locating trouble in the ignition system ofinternal"combustion engines, for instance, to

trouble. etc. 7

determine whet-her the trouble is caused by a fouled plug, a shortcircuit in the wiring connections, punctured insulation, magneto Furtherobjects and advantages will appear hereinafter.

The invention consists of the parts and the combination and constructionof parts as hereinafter more fully deseribedand claimed, havingreferenceto the accompanying drawings, in which- Figure 1. is a frontview of the testing instruinent. Fig. 2 is a cross section on line 2-2.,Fig. 1. Fig. 3 is a similar cross section showing a modification in theconstruction of the spark plugs. Fig.4 is a diagrainmatic view showingthe instrument connected for testing. Fig. ,5 is a diagrammatic viewshowing a modified form of construction.

More specifically described, the instrument comprises a cast metalcasing A, in 'which is formed an air tight compression chamber 2 towhich air may be admitted through a check valve 3 and registered by apressure gage 4. The casing is otherwise provided wilh a threadedopening 5 into which spark plugs, hereinafter called, testing plugs arescrewed. The casing is also'pi'ovided with a pair of glass coveredopenings 7,

' through which the terminals of the testing plugs are visible.

The testing plugs employed in the instrument are preferably constructedas shown in Fig. 1. That is, each plug consists of two separateinsulated terminals 89, which are independently secured by bushings1011. This construction permits insulation against high tensioncurrents, such as are now most commonly used, and also preventsshortcircuiting between the plug and easing, as no ground connection ismade with same.

Specification of Letters Patent.

Patent-ed May 25, 1915.

Application filed September 15, 1914. Serial No. 861,812.

The modified form shown in Fig. 3 is very similar, with the exceptionthat the two terminals 8 and 9 are mounted in the same insulator.

In operation, referring to Fig. 4 which 8'0 represents a two cylinderunit, the test is made as follows: The secondary wires 12-13 of themagneto are first disconnected with. their respective engine plugs 1415and are then connected with terminals 8 on the in.- "85 strumcnt testingplugs. Terminals 9 of testin plugs are then connected by wires 16-1 withthe" engine plugs I l-15 and these are in turn grounded by wire 18 inusual manner. The engine .can now be start- 9.

ed and is preferably made to run at a cornparatively slow speed whilethe test is being conducted. Air is now admitted into chainher 2 fromany suitable source, or forced in by pump 19 until the pressure withinthe 76 chamber is brought to correspond approximate-1y, or to a pointsomewhat above the, maximum pressure in the engine cylinder under fullcompression. If thespark passes through the testing plugs regularlyand80 properlyuinder such conditions, it may be quite safely assumed. thatthe spark is also jumping across the terminals of the plugs in theengine. ltg, lioivever, the sparks on one of the testing plugs, or both,begin to fail as the pressure increases in chamber 2, it

shows immediately that soifiething is wrong with the ignition system.For i'nstance, leakage may occur'in l'he viring or connections;

or the contact points in the distributor of the- 1 magneto may be settoo far apart or partly corroded, or 1 short circuit in the connectionsmay be found. The conductivity of air or vapor dcci'cascs with anincrease in' pressure. It can;' therefore be seen that if anyconnectionbetween the engine plugs and magneto are leaking or otherwisedefective, that as the pressure in chamber 2. is increased this defectwill iiniiiedintcly be indicated, as the resistance caused by thepressure within the chamber will be suilicient to prevent the current orsparlefroin jumping the gap between the terminals of the testing plug.

The construction of the testing instrument here shown jpermits theignition system, of any internal c )mbiistion engine to beitested Whilethe engine. is running. and,also eliminates the i'ie'ccssity of removingthe engine plugs while the test isbei'ng made.- The test can be made atvarious engine speeds;

this nn-viin pel tan t fehtnfe of present invention; as the currenoutput ofisome generators 1 0p magneifos \m'y greatly with (511311310insped;

- in Fig. 5 a slight modification is shoivn in which casing Aiseonstructe'd' of a pair of cross shaped pipe fittings 24 and 25. Thesefittlggs are connected together, but insulated froni each other, by afiber nipple26.. This commits w internal chambe in "the" fit. tings ndwas r ep n sea-1 3nd; in the j easing ind ex.- fltei'minels insnlateirgin ting iji r hngler; pressnre Into chambe ng 3 V, spark plug mopntefnding n hem erg s P535 1 t W fs' pe w im l pip e m, eimch pthei end thecesinggifdpenings, fprmed in mijs' ing' hieyin trsnspitient ,clbs uresmouhtedjehereji iii'i with j gje ternii check; valve I v misting airunder pres? sure ultethe conibinafie' lhe spark plugs in, an?,intq nelcombnsigien engine, and the chrrent supply jor.sen 1e,,ef testing spark,

in which the; ,lie'rn'n feering'seidpteesilre Q M I I Ixilte'etimonywhereof I-heve d 'ne i ic fiii l-lin' l,

' my hand i'n the presenee ef two su be M rgmi iwg se m circuit mum"ffmpply, a calm" plugs en 'engme plu and having e e amber in xed theren in whi the testing lugs'ere nntuhend in which the of mmy be observed.means for forcing e'il' tinder presumed nub said chamber. \y 1 4 A 5.The combination {wibh the speflg; ll'il in an internal combustion'engineen t 6 current supply forsaine, of 'ng spark plugs interposed on thehcilcui between the engine plu end-current pl', e

having a q ember formed th reihin Whig [the fleeting plugs are moan andin which the tei'mmals of 'sam'e mei be observed, means: fprfpr'cing airl nden pressure into ;nigl'- m e n Ne s? fl tawk m emmbimion-wihlwbs nmlugs .in enjntemnl eoinbuiion fen e, an

msp w it p Jthey file plugs and phrreint" v QM. er, there being oneunit" 16*" fend means for forcing sir-Lander presume intorthe eeveralunits. ;7. The in aninflernel combustione'n ,gl n'rnent supply telm, Off

served, midh-e ds i f ofunits -connected m I ll .wltlm W v Jump W. Cum,

0mm R. Tums.

t \e g eurrent supply 'forjen' (0450! Mamet-la plug v QCJAUfiE-HARLKN.

